•354 MR. J. B. SCKIVENOK, ON THE [June I913, 



are to be described with regard to the European geological sequence, 

 we find that the matter is not so simple as one might imagine. 

 This can be illustrated by extracts from the ' Manual of the Geology 

 of India' 2nd ed. (1893). On p. 121 it is stated that fossils from 

 the beds above the boulder-clay of the Salt Ilange show that they 

 are approximately contemporaneous with the marine Carboniferous 

 ■of New South Wales, and that these Australian beds were formerly 

 regarded as equivalent to the Lower Carboniferous of the European 

 sequence, but are now considered as Upper Carboniferous, if not 

 homotaxial with the Permo-Carbonif erous of Europe. 

 On p. 125 we read of the uppermost division of the Lower Productus 

 Beds :— 



'This fixes the homotaxis of these beds as Upper Carboniferous, or inter- 

 mediate between that and Permian.' 



On p. 127 we read of the Middle Productus Beds : — 



' These Mesozoic forms preclude us from assigning the group to an older 

 date than the Permian ' ; 



but the plate facing p. 126 has the legend ' Permo-Carboniferous 

 (Middle Productus Limestone) fossils.' 1 



The Talchir Boulder-Bed (p. 208) is referred to the Upper Car- 

 boniferous, and is regarded as belonging to the same horizon as the 

 boulder-bed of the Salt Eange ; but on p. 207 we also read that 



' the suggestion made by Mr. H. F. Blanford in 1875, that the Talchir Boulder- 

 Bed was contemporaneous with the Permian glacial deposits of England, has 

 never been absolutely disproved, and as recent investigations have shown that 

 the supposed Lower Carboniferous deposits of Australia are newer than tbey 

 were formerly considered to be, it is still possible that this may be the true 

 ■equivalence.' 



Then the base of the Productus Beds may be Permian also? 



The glaciation may, therefore, have occurred at any time from 

 the Upper Carboniferous to the Permian. The extracts concerning 

 the Productus Beds alone, given above, show that the glaciation 

 may have been at least as late as the Permo-Carboniferous. In 

 Sir Archibald Geikie's 'Textbook of Geology' occurs the following 

 "passage, illustrating this doubt as to the date of the late Palaeozoic 

 glaciation : — 



'The evidence now accumulated from South Africa, India, Cashmere, and 

 Australia, seems to point to some general operation on a gigantic scale in the 

 southern hemisphere at the close of the Carboniferous or in the Permian 

 Period.' (4th ed. vol. ii, 1903, p. 1060.) 



This is interesting and important, in connexion with the Malayan 

 glacial deposits and the underlying Baub Series. If the glacial 

 "beds were assumed to be Upper Carboniferous, with no alter- 

 native — then the palseontological evidence which points to the 



1 Dr. E. W. Vredenburg, in his ' Summary of the Geology of India ' (1907), 

 gives on p. 42 the following classification of the Productus Beds : — 



Lower Productus and lower part of the Middle Productus Beds = Upper 

 Carboniferous. 



Remainder of Productus Limestones=Lower Permian (Permo-Carboni- 

 ferous or Artinskian). 



